15CrMoG is a pearlitic heat-resistant steel alloy pipe. "15" represents a carbon content of approximately 0.15%, "Cr" (chromium) content of approximately 1.0%-1.5%, and "Mo" (molybdenum) content of approximately 0.4%-0.6%. "G" indicates its suitability for high-pressure boiler piping. 15CrMoG steel pipe exhibits enhanced high-temperature resistance and pressure resistance through the addition of elements such as chromium and molybdenum.
Core Characteristics
Excellent High-Temperature Performance
Thermal Strength: Tensile strength ≥440MPa, yield strength ≥235MPa at 500-550℃, maintaining structural stability even during long-term operation.
Oxidation Resistance: A dense oxide film forms on the surface, effectively resisting high-temperature oxidation corrosion and extending service life.
Hydrogen Corrosion Resistance: Hydrogen permeability is reduced through alloy element optimization, avoiding the risk of hydrogen embrittlement.
Low-Temperature and Corrosion Resistance
Good toughness is maintained even at low temperatures (e.g., below -20℃), preventing brittle fracture.
Suitable for transporting corrosive media containing sulfur, chlorine, etc., such as in catalytic cracking units in the petrochemical industry.
Microstructure Stability
After long-term high-temperature operation, the microstructure may undergo pearlite spheroidization, but this process can be significantly delayed through normalizing and tempering heat treatment (as required by the supplier), ensuring stable material properties.
High Welding Process Requirements
Poor Weldability: Due to the presence of elements such as chromium and carbon, there is a significant tendency for hardening, making it prone to cold cracking.
Welding specifications: Preheating to 150-200℃ is required. Use low-hydrogen electrodes (such as R307) or matching welding wire (such as ER80S-B2L). Post-weld tempering at 715℃ is necessary to relieve welding stress and improve joint performance.
Chemical Composition and Mechanical Properties
Components Content Range (%)
Carbon (C) 0.12-0.18 Increases strength, but excessive amounts reduce weldability.
Chromium (Cr) 0.80-1.10 Enhances high-temperature oxidation resistance and corrosion resistance.
Molybdenum (Mo) 0.40-0.55 Improves thermal strength and resistance to hydrogen corrosion.
Silicon (Si) ≤0.50 Deoxidizer, improves fluidity.
Manganese (Mn) 0.40-0.70 Deoxidizer, increases strength.
Mechanical Properties:
Tensile Strength: 440-640MPa
Yield Strength: ≥235MPa
Elongation: ≥21%
Hardness: ≤179HB (Brinell Hardness)
Application Areas
Power Industry:
High and medium pressure pipelines, headers, and superheater tubes in power plant boilers with steam parameters of 510℃.
High-temperature and high-pressure fluid transport systems within the containment vessel of nuclear power plants.
Petrochemical Industry:
Key equipment such as catalytic cracking units, hydrogenation reactors, and high-temperature heat exchangers.
Transporting corrosive media such as sulfur-containing crude oil and natural gas.
Other Fields:
Pressure-resistant pipes for marine boilers and superheaters (compliant with GB5312 standard).
High-pressure fertilizer equipment (compliant with GB6479 standard), petroleum cracking units (compliant with GB9948 standard), etc.